We just started using some Shorthorn sires, AI, on high-percentage Angus & Simmental cows this year, so I can't make any hard & fast, or experienced comments - but I've relied on a number of friends who have been in the Shorthorn 'business' for decades for some recommendations.
One, from a fellow vet who breeds some Shorthorns, in addition to Maines & Red Angus:
"The current Shorthorn breed (IMO) has 2 different components (although they try to sell it as one) the show and the real world - so I think you would need to do some due diligence to find the right bull(s).
The Shorthorns are all over the board in terms of frame score and WDA, ADG - many of the popular bulls are not at all consistent. Also there are very few real calving ease bulls in the breed, especially when you get into the "show" world. There are a couple of Shorthorn bulls that do downsize if that is an issue.
Both TH(tibial hemimelia) and PHA(pulmonary hypoplasia/anasarca) can be a problem with Shorthorns - although most of the PHA comes thru the very popular show bull Double Stuff (who incidentally carried both TH and PHA) but with Maines allowed into the herd book there are other ways to get PHA. Many Shorthorn breeders are not testing for PHA despite the fact that the pedigree suggests they should ."
Some of the 'real-world'/commercial type Shorthorn breeders that have been recommended to me include(in no particular order):
Kaper Cattle Co. -
http://www.kapercattle.com/
The Bighams at Elbee Farms -
http://www.elbeefarms.com/aboutus.html
Rob Sneed (RS Shorthorns in MO) - I really like the 034X bull he bred - will be using him here, at some point, at least on 2nd-calvers.
Lakeside Shorthorns in MI -
http://www.lakesideshorthorns.com/bulls.html
Currently, we're using some of the Waukaru bulls - mainly because they're readily available from Origen through our ABS rep , but as I've studied the thing out, I've been impressed with the performance and carcass testing that the Jordans have done with straightbred and Shorthorn-cross calves sired by their bulls. They also have GeneStar data available on many of their sires and bull offerings, if you're interested in incorporating those factors into your breeding plan.
Currently have one Goldmine 2109 heifer on the ground, several coming this spring, and we started using Coppertop 464 on mature cows this fall.
http://www.waukaru.net/